Complexation reaction on the immobilized matrices: Complexes of iron (III) hexacyanoferrate (II) and some N, O and N, S containing.ligands formed on a thin gelatin layer

Abstract

Complexation reaction occurring between mixed potassium- iron(III) hexacyanoferrates(II), KFe[Fe( CN)₆], and N, S or N, O-Containing ligands such as 8-hydroxyquinoline (1) and its alkyl- and oxyalkyl derivatives, 1-nitroso-2-naphthol (2) and its isomer 2-nitroso-Inaphthol, isonitrosoacetone (3), <em>a</em>-benzoinoxime (4), 8-mercaptoquinoline (5) and some of its substituted derivatives (halide, alkyl, S-methyI), dithiooxamide (6) and its N,N' -diphenylsubstituted derivatives have been studied in thin gelatin layers. With KFe[Fe(CN)₆]-matrix, complexation proceeds according to pseudo- SN l-mechanism. The complexation occurs after iron(III) hexacyanoferratet(Il) dissociates in the alkaline medium which proceeds according to two possible ways; one leads to Fe₂O₃ and [Fe(CN)₆]^4- anion, the other to Fe(OH)₂ and [Fe(CN)₆]^4-anion. It is noted that in the case of N, O-containing ligands, Fe (ll) chelates are formed and in the case of N, S-containing ligands, Fe (lll) chelates are formed, It is shown that in the case of N, S containing ligands, there is a participation of molecular oxygen in the complexation reactions. Examples of kiaetic curves for the particular systems "potassium, iron (III)-hexacyanoferrate (II) ligand" are presented.